I am not saying a wrist brace is bad. If you have an injury that prevents you from cupping your wrist then by all means, use one.
Still, I think going to a lower ball weight is a better option. My reasoning for this is very simple. You do not get the same type of "feel and control" with a wrist brace.
I believe that this is crucial to being able to adjust properly, especially on more difficult shots. Increasing or decreasing your rev rate or axis rotation is talked about in general, but most do not explain how to do it. The truth is that once you learn how to, you have to learn how much. These types of adjustments are as much about feel as they are about technique.
Take shooting pool as an example. Ones you learn how to use English on the cue, you have to learn how much to use on each shot, taking into consideration playing surface, ball speed control and desired ball placement. While this is oversimplified, my point is that "feel" ultimately dictates the shot, at least for good players.
For me, bowling is the same. The wrist brace interferes with me feeling the ball and the adjustments being made. Without that feel, it is difficult to make those incremental adjustments that I believe are necessary to improve as I desire.